Switching mode regulators have wide application as low loss power supplies. One particular application is at the front end of power rectifiers where they are controlled, by pulse width modulation techniques, to provide enhanced power factor at the input AC power line feed. Regulators are chosen which are highly efficient so that the overall power processing system is highly efficient. Accordingly switching regulators are designed using controlled wave forms and careful timing to minimize losses at the switching transitions of the various non-linear switching components. These regulators are embodied in circuit topologies that emphasize near zero or zero-voltage switching. In zero voltage switching the conductivity transition to the conducting state of the active power switch occurs when the voltage of the power switch is at a substantially zero level. In some arrangements other switching components of the circuit may be controlled to switch at a zero or near zero voltage.
A particular example of such a circuit is a boost regulator designed to achieve zero or near zero voltage switching. Such a circuit may indeed achieve the low loss or lossless switching criteria for at least the active power switch but the very circuitry added for achieving near zero or zero-voltage switching induces other transient phenomena that reduces the efficiency gains of zero voltage switching and further induces undesirable stress on other circuit components of the power regulator.